918541-45-4Relevant academic research and scientific papers
Chiral Coalition in Helical Sense Enhancement of Copolymers: The Role of the Absolute Configuration of Comonomers
Arias, Sandra,Rodríguez, Rafael,Qui?oá, Emilio,Riguera, Ricardo,Freire, Félix
, p. 667 - 674 (2018)
Both the role of the absolute configuration and the tendency of a chiral monomer to promote a certain helical scaffold in a poly(phenylacetylene) (PPA) have been evaluated to study the communication between two chiral monomers within a copolymer chain. Nineteen different PPA copolymer series - 47 helical copolymers altogether - were prepared to explore the existence of a chiral-to-chiral communication mechanism. From the data obtained, we found that communication between two different chiral monomers emerges when both exhibit two special features: (a) a different conformational composition - one must exist in a single low-energy conformation ( chiral Sergeant ) and the other must present two conformers ( chiral Soldier ) - and (b) the induction of a similar scaffold in the PPA, either cis-cisoidal or cis-transoidal. In the selected systems, the chiral Soldier includes the 4-ethynylanilide (para position) of either (R)- or (S)-2-methoxy-2-phenylacetic acid pendants characterized by their conformational flexibility (equilibrium between synperiplanar and antiperiplanar conformations). The chiral Sergeant contains the same chiral groups but linked to the backbone in meta position [3-ethynylanilide of (R)- or (S)-2-methoxy-2-phenylacetic acid] and is selected on the basis of its restricted antiperiplanar conformation. Incorporation of a very small amount (1%) of the Sergeant into a chain composed of just the Soldier transforms the originally axially racemic chain into a helix with strong sense preference (either M or P) that is determined by the absolute configuration of the Soldier.
Amino-5-(6-membered)heteroarylimidazolone compounds and the use thereof for beta-secretase modulation
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Page/Page column 19, (2008/06/13)
The present invention provides a 2-amino-5-heteroaryl-5-phenylimidazolone compound of formula I The present invention also provides methods for the use thereof to inhibit β-secretase (BACE) and treat β-amyloid deposits and neurofibrillary tangles
2-Amino-5-piperidinylimidazolone compounds and use thereof for beta-secretase modulation
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Page/Page column 12-13, (2010/11/28)
The present invention provides a 2-amino-5-piperidinylimidazolone compound of formula I The present invention also provides methods and compositions for the inhibition of β-secretase (BACE) and the treatment of β-amyloid deposits and neurofibrillary tangl
